Portable speakers are often used with portable electronic devices such as for example, CD players, MP3 players, laptop or notebook computers, and PDAs. To be portable they are normal compact. Being compact, there is minimal separation of the electronics, and the drivers of the speakers. Vibration caused by the drivers can induce distortion into the sound to affect quality by causing vibration of the electronic circuitry and components built-in to the portable speakers. Such induced distortion is sometimes called a microphonic effect. Due to size constrains, this problem is not addressed in compact, portable speakers.
Furthermore, the vibration of the drivers can also induce sympathetic vibration in mechanical components of the portable speakers such as, for example, battery spring terminals. Such sympathetic vibrations may be audible to a user.
Also the drivers of speakers are prone to damage and must be protected when not in used. This often entails used of a grille, or other obstruction in front of the drivers, thereby affecting sound quality.